The present application relates to a dial speed indicator, with a second pointer indicating a reference speed.
The dashboard of a motor vehicle usually comprises an instrument panel, located facing the driver, which comprises a group of indicators, in particular a speed indicator, which may have a pointer.
The speed indicator pointer, controlled and rotated by a motor, or movement, usually lies in front of a printed surface carrying reading marks (graduations and speed values, in particular), forming a speed dial. The reading mark surface is called the dial plate. The speed indicator is mounted in a dashboard hood serving as protection and cover and supporting a protective window.
It has become common to want to display a reference speed on the speed dial, whether it be the reference speed of a cruise control or a speed limiter, for example. The driver can thereby read, on the same indicator, the actual speed of the vehicle and the speed to which he has adjusted his engine, or that he must not exceed, in those cases. This reading must be able to be carried out by day as well as by night.
The prior art provides speed indicators in which a series of light-emitting diodes (LED) is placed at the outer edge of the dial, the LED that corresponds to the reference speed being illuminated. Having so many LEDs is however very expensive and considerably increases the cost of the instrument panel. The accuracy of the indication of a speed, which is subdued because of the juxtaposition of the LEDs, is also quite poor.
PCT Publication WO 2001/92047 provides an indicator which includes a first pointer indicating the actual speed of the vehicle, lying in front of the dial plate, and a second pointer, angled, indicating a reference speed and located at the rear of the dial plate, of which only the end of the angled portion can be seen at the outer edge of the dial. The indicator comprises a first light box, at the back of which are mounted, on a first printed circuit board, LEDs for illuminating the dial pointed to by the pointer indicating the actual speed, and a second light box, in which lies the angled pointer, the dial pointed to by this pointer being illuminated by LEDs mounted on a second printed circuit board located at the rear of the second light box, and also carrying a drive motor for the two pointers. This indicator is however very voluminous, due to the depth required for the combination of the two pointers and the means for driving and illuminating. In addition, the pointers are not illuminated.